What is heat? What is temperature? What is energy? What is time? When we look beneath the surface of these everyday terms to learn how scientists understand them, we encounter a realm of fundamental processes that rule the universe.

13 How Materials Respond to Heat 14 Phases of Matter-Gas, Liquid, Solid 15 Phase Diagrams-Ultimate Materials Maps 16 Properties of Phases 17 To Mix, or Not to Mix? 18 Melting and Freezing of Mixtures 19 The Carnot Engine and Limits of Efficiency 20 More Engines-Materials at Work 21 The Electrochemical Potential 22 Chemical Reactions-Getting to Equilibrium 23 The Chemical Reaction Quotient 24 The Greatest Processes in the World